Earlier this month (9/4) our dishwasher started leaking, and I disconnected it. The new dishwasher comes in about a week, but I was curious whether I would see an increase in our water usage from hand washing the dishes. After downloading the data, though, there were more interesting slope changes:

I think most of these make sense:

Here's how I see water usage changing:

• Decrease when we bought the house, because unit two was vacant until we were ready to move in, then an increase when we moved in.

• Temporary decrease when we moved out because of a mercury spill, but not all the way to zero because the first floor was still occupied (two people).

• Temporary decrease when we moved out to have dormers installed, but a smaller one than before because both the first and second floors were still occupied (four people).

• Sharp decrease at the end of March 2018, when we replaced the very old top loading washing machine broke and we replaced it with a new high-efficiency front-loader.

Here's a similar chart, with years stacked:

Comparing just 2017 and 2018 the change from the washing machine is pretty dramatic:

How much water did that save us? We've had the new washer for 171 days and used 30k gal, while during the corresponding 171 days last year we used 46k gal, so 16k gal more. Our cost per gallon (water and sewer) is 1.65¢, so simple extrapolation says we're saving $584/y on water with the new machine. Plus a substantial fraction of those saved gallons were heated, so we're saving fuel too.

This is a washer that gets a lot of use (average of seven adults and two kids) but with these sorts of savings we should have done it sooner!